Distorting the lens

Feb 09, 2012

An optical image of the effects of a gravitational lens: the distorted view of a distant galaxy as seen after its light passes through a closer galaxy whose gravity twists the image into a ring. Credit: ESA/NASA and Hubble

(PhysOrg.com) -- One of the most bizarre predictions of Einstein's Theory of General Relativity is the existence of back holes, objects that are so dense that not even light can escape from their gravitational grasp. A related prediction of General Relativity is that the path light travels can be bent by the presence of mass, so that matter can sometimes act like a lens - a so called "gravitational lens" - and produce distortions in images of background objects seen behind it. During the now famous total eclipse of 29 May 1919, scientists confirmed these basic predictions of Einstein's theory by observing starlight bent by the gravity of the Sun.

Astronomers since then have seen many cosmological examples of gravitational lensing, as light from a distant galaxy is magnified and distorted as it passes through a closer galaxy (or a cluster) en route to Earth. CfA astronomers Avi Loeb and Rosanne Di Stefano, with three colleagues, have now calculated the effect when the gravitation lens (the galaxy) also contains a supermassive black hole. Since most if not all galaxies host supermassive black holes, the added complexity of the image could be common.

The scientists conclude that a central supermassive black hole can indeed distort the image of a more distant galaxy by introducing new knots in the image. These new features are usually very faint, however, and will probably be undetectable with current instruments. However, the team notes that new facilities, especially at radio wavelengths, should be able to detect them, and when interpreting the distorted shape of a gravitationally imaged galaxy, the implications of a central supermassive black hole needs to be be taken into account.

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Re: "The scientists conclude that a central supermassive black hole can indeed distort the image of a more distant galaxy by introducing new knots in the image. These new features are usually very faint, however, and will probably be undetectable with current instruments. However, the team notes that new facilities, especially at radio wavelengths, should be able to detect them, and when interpreting the distorted shape of a gravitationally imaged galaxy, the implications of a central supermassive black hole needs to be be taken into account."

This is diabolically clever! Are we seeing a researcher priming his audience for an inference which would otherwise validate an electrical plasma cosmology? After all, radio-observed knots occur in electrical plasmas when the current density reaches a threshold value. In that competing view -- the Electric Universe -- the lensing is not happening, and these filaments are instead Birkeland Currents.

The researchers aren't studying plasma physics and the images resulting from gravitational lensing are not electricity but luminescence. The point of the article is that scientists are close to reconstructing a view of galaxies we know to exist because of the intervening masses in our line of sight providing a magnified albeit distorted view of them through gravitational lensing. What is important is that we would not otherwise have an image of that galaxy, so in effect, those images are a peek into a past we might otherwise never see.

Re: "The researchers aren't studying plasma physics and the images resulting from gravitational lensing are not electricity but luminescence."

You might want to check your astrophysical textbook. 99% of what we see with our telescopes is matter in the plasma state. There is no controversy in this. The controversy occurs with regards to the models for the plasmas: Astrophysicists are modeling the cosmic plasmas as though they are fluid- or gas-like, deprived of their electromagnetism. This is completely contrary to the behavior we observe in the laboratory -- which is electrical. Do you really believe that cosmic plasmas are different from laboratory plasmas?